How quickly does the aortic valve progress?

Aortic Valve Disease: Depends what condition you're asking about. There is a difference between leaking and narrowing, and then within each condition, progress is depending upon the cause of the problem. Since many parameters are involved, discuss with your doctor who has all the needed info.

Stenosis?: Or regurgitation? Highly variable.

Depends on cause: It depends on the cause and the type of aortic valve disease is present.